Stabilization of levinstein mustard gas



Patented Mar. 16, 1954 STABILIZATION OF LEVINSTEIN MUSTARD GAS RudolphMacy, Baltimore; Md., assignor to the Unitedstates of America asrepresented by the Secretary of War narrating; Application May 1, 1945,

1. ser al 2 Claims. (01." 260-609) (Granted under Title 35, u. s.ooae*(1952-);-

sec. 266) The invention described herein may be manufactured and used byOr for the Government, for governmental purposes, without the payment tome of any royalty thereon.

This invention relates to the stabilization of Levinstein mustard. Themost important chem ical warfare vesicant agent known to date is theagent known as mustard gas. Chemically, pure mustard gas or mustard isbis-(beta-chloroethyl) sulfide, Although there are several processes formanufacturing mustard, the most important method in this country is thesocalled Levinstein process. The product of the Levinstein process iscommonly known to those skilled in the art as Levinstein mustard.

Levinstein mustard is a relatively impure product, and the dichlorethylsulfide content thereof is in the neighborhood or" 70%. The impuritiesin Levinstein mustard are of a complex nature and have not beencompletely determined to this date, but are essentially polysulfides ofthe composition (C1CH2CH2)2SI- Although Levinstein mustard has veryeffective vesicant properties, and is substantially equivalent to puremustard from the vesicant standpoint, it does have the serious objectionof being unstable over long periods of storage in steel containers,especially at temperatures of 110 to 158 F. l'he exact reasons for thedegradation of Levinstein mustard in storage have not been fullydetermined in all respects. However, it is known that the instability isdue to certain impurities present, since the pure product is notunstable under normal storage conditions. A number of theories have beenadvanced from various sources as to the causes of the instability ofLevinstein mustard. Corrosion of steel containers by the mustardmolecule is probably due to its inner salt nature, and in the case orLevinstein mustard this is enhanced by presence of polysulfidescontaining labile sulfur. Because of these polysulfides, iron actuallydissolves in Levinstein mustard at slightly elevated temperature.Levinstein mustard is very stable in glass containers, or in steelcontainers coated with a properly haired-on suitable lacquer.

Regardless of the exact reasons for the instability of Levinsteinmustard, the problem is fully recognized and is extremely serious duringtime of war and national emergency when it becomes necessary to build upa, very great strategic reserve of this chemical warfare agent incontemplation of the fact that chemical warfare may, at any time, beresorted to.

From a practical standpoint it is necessary to store the bulk of thestool; pile of Levinstein mustard in steel drums. Logistical reasonsmake it necessary to have a sizable proportion of Levinstein mustardsupply located in tropical, or near tropical, regions. The hightemperatures in such regions greatly hasten the deterioration ordegradation of the Levinstein mustard stored in such regions. During thespoilage or deterioration of Levinstein mustard, pressures develop inthe steel drums, and eventually, if the product is not used, thedeterioration is carried to the point where it is necessary to destroythe portion of the supply which has so deteriorated.

Although the above outlined problem has been known since World War I,when Levinstein mustard was produced and stored on a large scale, therehas been heretofore no satisfactory method or means of stabilizingLevinstein mustard with respect to chemical decomposition anddevelopment of pressure. A great amount of research efiort has beendevoted to the problem. However, prior to this invention, the netresults of such previous research and investigation of the problem onlyindicated that ammonia was a partially effective stabilizer forLevinstein mustard, and that partial stabilization could be obtained bythe use of small amounts of strong bases. However, none of these methodsor means of stabilization were at all satisfactory from a practicalstandpoint.

Accordingly, the object of this invention is to provide a practicaleffective means of stabilizing Levinstein mustard. so as to prevent to alarge degree its deterioration in storage. Briefly stated, the means ofstabilizing Levinstein mustard provided by this invention, consists inadding thereto small amounts of certain amines which have been foundeffective for this purpose. The amines, which are presently preferred asstabilizers of Levinstein mustard, are: morpholine,hexamethylenetetramine, dimethyl amine, triethylene tetramine, andtetraethylene pentamine.

Specifically, 0.5% hexamethylenetetramine, 1% of dimethyl amine, and 1%of morpholine have been found to be effective.

The nature of this invention having been broadly outlined above, andpreferred embodiments of the invention having been described, it will beapparent that certain modifications and additional formulations willsuggest themselves to those skilled in the art. Accordingly, it isintended that the foregoing descriptive material 3 shall be interpretedas illustrative and not in a limiting sense. Iclaim:

1. A stabilized mixture consisting essentially of bis-(beta chlorethyl)sulphide and sulphides having the formula ('ClCHzCHz) 281 andmorpholine, said morpholine constituting by Weight 1% of said mixture.

2. The method of stabilizing a mixture consisting essentially ofbis-(beta chlorethyl) sulphide and sulphides having the composition(C1CH2CH2)2S1:, said method consisting essentially in adding morpholineto said mixture in an amount constituting, by Weight, 1% of the weightof said mixture.

RUDOLPH MACY.

4 References Cited in the file of this patent UNITED STATES PATENTSNumber Name Date 1,719,168 Chamberlain July 2, 1929 1,903,287 Cox Apr.4, 1933 2,043,259 Messbach June 9, 1936 2,268,608 McNulty Jan. 6, 19422,498,684 I-Ium Feb. 28, 1950 OTHER REFERENCES Lawson et al., JournalAm. Chem. Soc," vol. 47, pp. 282l-S6l1925). (Copy in ScientificLibrary.)

Mann et a1., Industrial 8; Eng. Chem., vol. 28., No. 2, Feb. 1936, pp.159-163. (Copy in Scientific Library.)

1. A STABILIZED MIXTURE CONSISTING ESSENTIALLY OF BIS-(BETA CHLORETHYL)SULPHIDE AND SULPHIDES HAVING THE FORMULA (CLCH2CH2) 2SX AND MORPHOLINE,SAID MORPHOLINE CONSTITUTING BY WEIGHT 1% OF SAID MIXTURE.